1. Field of the Invention
The present invention relates to a method of peeling a semiconductor chip used in a semiconductor device manufacturing process. Also, the present invention relates to a device therefor.
2. Description of the Related Art
Conventionally, a semiconductor device is manufactured in such a manner that, for example, a plurality of semiconductor elements are formed on the first surface of a silicon wafer (semiconductor substrate), and this silicon wafer is diced so as to separate the semiconductor elements (silicon chips) from each other. The silicon wafer is adhered to a dicing tape before the dicing, and when dicing is completed, the silicon chips, which are separated from each other, are adhered to the dicing tape. The silicon chip is peeled from the dicing tape, by a peeling device, before die-bonding.
In order to peel the silicon chip from the dicing tape, a needle device 34 shown in FIG. 11 is conventionally used. The needle device 34 includes needles 34A. The needles 34A are moved from the lower side of the dicing tape 24 toward the dicing tape 24 and penetrate the dicing tape 24 so that the silicon chip 16 is lifted. There is also provided a needle device in which the needles 34A do not penetrate the dicing tape 24.
Japanese Unexamined Patent Publication No. 10-189690 discloses a peeling device, in which needles are arranged at positions close to the four corners and at a position close to the center of a silicon chip. The needles arranged at the positions close to the four corners are operated first, and then the needle arranged at the position close to the center is operated, so that the silicon chip can be peeled off stepwise from the four corner portions toward the central portion.
Japanese Unexamined Patent Publication No. 6-338527 discloses a peeling device in which needles are not used but a silicon chip is peeled off from a dicing tape by attracting the dicing tape from the lower side thereof by a peeling device having suction grooves. Japanese Unexamined Patent Publication No. 2001-118862 discloses a peeling device in which a dicing tape is peeled off from a dicing tape, by attracting the dicing tape from the lower side thereof by suction grooves and moving a stage in parallel.
Recently, there has been an increasing demand for reducing the thickness of a silicon wafer and the thickness of silicon chips. However, as the thickness of the silicon wafer is reduced, it becomes difficult to peel the silicon chips from the dicing tape. For example, when the thickness of the silicon chip is reduced, there is a tendency that the needles pierce the silicon chip after they have penetrated the dicing tape.
Further, when the thickness of the silicon chip is reduced, it tends to be deformed. For example, as shown in FIG. 12, the dicing tape 24 and the silicon chip 16 are deformed into concaved shapes at positions where the needles 34A come into contact with the dicing tape 24 and the silicon chip 16 as shown in FIG. 12. Therefore, the silicon chip 16 may be damaged or cracked. A similar problem arises in a case where the dicing tape is attracted from the lower side thereof by suction grooves.
Further, in order to peel the silicon chip 16 off from the dicing tape 24, it is necessary that air enters the interface between the silicon chip 16 and the dicing tape 24 and spreads over the interface. In the case where the needles do not penetrate and tear the dicing tape 24, air does not enter the interface first at the central portion of the silicon chip 16, but air enters the interface in the outer circumferential portion of the silicon chip 16. Therefore, peeling occurs only in the outer circumferential portion of the silicon chip 16. In the circumstance shown in FIG. 12, it becomes difficult for the silicon chip 16 to be peeled off from the dicing tape 24, and the silicon chip 16 tends to be damaged.
It is an object of the present invention to provide a method of peeling a semiconductor chip and a device thereof capable of securely peeling a semiconductor chip off from a dicing tape even when the thickness of the semiconductor chip is thin.
A method of peeling a semiconductor chip, according to the present invention, comprises the steps of peeling a semiconductor chip, adhered to a tape, from the tape using a peeling device including a plurality of annular contact members arranged one after another from the outside to the inside, wherein the plurality of annular contact members are operated so that the semiconductor chip is successively peeled off from the tape from an outer circumferential portion thereof toward a central portion thereof.
A device of peeling a semiconductor chip, adhered to a tape, from the tape, according to the present invention, comprises a plurality of annular contact members arranged one after another from the outside to the inside, and an operation device for operating the plurality of annular contact members so that the semiconductor chip is successively peeled off from the tape from an outer circumferential portion thereof to a central portion thereof.
In the above method and device, the semiconductor chip is successively peeled off from the tape from the outer circumferential portion toward the central portion by the peeling device including a plurality of annular contact members which are arranged one after another from the outside to the inside in order. Accordingly, even when the thickness of the semiconductor chip is small, the semiconductor chip can be securely peeled off from the tape.